The Saigetsugan is a dōjutsu kekkei genkai which is held by the Tsukiyoha Clan and was originally the Sharingan but mutated due to being manipulated by a seven scientist who wished to "enhance" the Sharingan. Since the Uchiha clan was completely wiped out it is considered to be one of the great dōjutsu, along with the Byakugan and Rinnegan.